Ambient Temperature Affects Offspring’s Metabolism

Study of high relevance in the face of impending climate change

Even minor changes in environmental temperature during pregnancy can profoundly affect the metabolism of the offspring – this previously unknown connection has now been demonstrated by a research group from Lübeck including Dr. Rebecca Oelkrug and Prof. Jens Mittag.

It has long been known that the predisposition for metabolic or endocrine disorders can be affected by events in utero. This usually occurs through epigenetic modifications on the fetal DNA, which are programmed by e.g. life style or environmental factors. This mechanism is usually used by mammals to allow a flexible metabolic adjustment in the next generation to changes in the environment, e.g. food availability.

In humans, these factors are however often disconnected from the real conditions, leading to improper adjustment and the risk for metabolic disorders later in life. The example that has been most studied is the observation that children from obese mothers also develop obesity later in life. The current study by Oelkrug et al, which has been published in the prestigious journal Cell Reports, now provides evidence that also the ambient temperature and the amount of maternal thermogenesis affects the fetal metabolic programming of the offspring.

“Most remarkably, a lower ambient temperature during pregnancy not only affected the length of the offspring, but also reduced their muscle growth, which lead to a higher risk for type II diabetes later in life”, explains Prof. Jens Mittag, one of two directors of the newly founded Institute for Endocrinology and Diabetes of the University of Luebeck. Dr. Rebecca Oelkrug, first author of the study, who is currently eight months pregnant herself, adds that there is likely no reason to panic. “The changes we found in muscle growth and metabolism of the affected offspring could be reversed by exercise in adulthood.”

The researchers suspect that epigenetic modifications on the fetal DNA may have caused these alterations in muscle growth, and that these modifications can be erased by sufficient physical activity or exercise later in life. “A primary aim of our research has been to identify possible risk factors during pregnancy to allow the best possible care for pregnant women and their babies”, says Dr. Oelkrug. However, since all studies were conducted in an animal model, the first step now would be to conduct epidemiological studies in cohorts of pregnant women and their children to confirm that the results can be transferred to humans. Nevertheless, given the ongoing climate change, the results are likely of high relevance not only for humans but also for other mammalian species, including domesticated animals.

The precise metabolic pathways or hormones that change in mothers in response to altered ambient temperature are currently being dissected by the researchers in a follow-up study that has been generously funded by the German Research Council DFG recently.

Rebecca Oelkrug, Christin Krause, Beate Herrmann, Henrik Oster, Henriette Kirchner, Jens Mittag (2020) Maternal Brown Fat Thermogenesis Programs Glucose Tolerance in the Male Offspring. Cell Reports 33 (5) 108351